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Showing 1 to 20 of 42 for “"R-me"”.
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Synthesis and Reactivity of Trimethylsilylthiolate Compounds: Precursors for Heterometallic Complexes
… (19, R = Me; 20, R = $\rm CH\sb2SiMe\sb3)$ react with $\rm MeOSO\sb2CF\sb3$ to form $\mu\sb3$-thiolate complexes $\rm\{Ru(N)R\sb2\}\sb3(\mu\sb3$-SMe)($\mu\sb3$-S) (22, R = $\rm CH\sb2SiMe\sb3$; 23, R = Me). Complex 19 reacts with ($\rm …
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Further studies of group 14- cobalt carbonyl chemistry
… carbonyl clusters with transition metal carbonyl anions and the reactions of Et₄NSnCl₃ with group 14-cobalt carbonyl compounds of the form R₃M'Co(CO)₄ (R₃ = Me, ⁿBu, Ph, Cl, Br; M' = Sn, Ge, Si). Further studies of the reaction between MeGeH₃ and Co₂(CO)₈ have led to a new proposal …
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Synthesis and characterization of hafnium and molybdenum bifunctional initiators for the preparation of triblock copolymers
… mixed alkyl hafnium complexes containing the (MesNpy)2 ligand ([(MesitylNCH2)2CMe(2-CsH4N)]2) were synthesized. (MesNpy)Hf(Neo)R ((2b), R = Me; Neo = CH2CMe2Ph) and (MesNpy)Hf(CH2TMS)(R), ((3b), R = Me and (4b), R = i-Bu)) were activated with {Ph3C} {B(C6F5)4} and one alkyl group was …
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Synthesis and catalytic evaluation of chiral ferrocenyl p^p and p^n palladium(II) complexes
… R = H SPNa and R = Me SPNb first prepared by Togni, and the P,P-type chiral ligands (η5-C5H5)Fe(η5-C5H3-PR2)C*H(OH)(PPh2) R = Ph SPPa, R = i-Pr SPPb of the Josiphos family. In these ligands, the methyl group on the stereogenic carbon is replaced with a hydroxyl group. …
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Some chemistry of Group IVB-cobalt carbonyl compounds
The reaction of MeGeH₃ and Co₂(CO)₈ has been reinvestigated. Products obtained from this reaction include MeGeCo₃(CO)₁₁, Me₂Ge₂Co₄(CO)₁₄ (or [MeGeCo(CO)₄]₂Co₂(CO)₆), MeGeHCo₂(CO)ₓ (x = 7 or 8), (MeGe)₂Co₄(CO)₁₁ and Co₄(CO)₁₂, the relative proportion depending on the ratio of the reactants. …
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The synthesis and reactivity of binuclear μ-hydrocarbyl complexes of some transition metals
The new μ-(l,n)-alkanediyl compounds [(ƞ⁵-C₅R₄Me)Fe(CO)₂ ]₂{μ-(CH₂)n}, (R = H, n = 3 -10 and R =Me, n =3 - 6), [Mn(CO)₅]₂{μ-(CH₂)n} (M = Mn, n = 4-6 and M = Re, n= 3 and 4) have been prepared using essentially two synthetic routes. Thus the iron compounds were synthesized by the reaction of …
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Ring-opening metathesis polymerization of 3-substituted cyclooctenes initiated by group 6 alkylidene complexes
… cis,head-to-tail (cis,HT) selective ring-opening metathesis polymerization of 3-substituted cyclooctenes (3-RCOE; R = methyl, hexyl, phenyl) initiated by high oxidation state M and W alkylidene complexes is described herein. W(NtBu)(CHCMe₃)(pyr)(OHMT) combined high cis,HT selectivity (>98% cis,HT) …
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Main Group Elements in Catalysis: Alkene/Alkyne Activation Using Organoaluminium(III)–Pyridyl Dimers
… to the commonly used precious transition metals, as well as its high Lewis acidity and ability to change oxidation state, aluminium has been widely explored as the basis for a range of single-site catalysts. This work details the development of new cationic Al(III)-based catalysts for …
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Intra- and intermolecular reactivity of organic diacyl systems
The mechanism or a thermal amino group transfer-fragmentation reaction yielding carboxyamides from mixed phosphoric-carboxylic anhydrides (RO(R¹R²N)P(O)OC(O)R³; R = R¹ = alkyl; R² = H, alkyl, aryl; R³ = alkyl, aryl) was elucidated from structure reactivity studies using a model system, R = R¹ = R² …
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A new synthesis of enantiomerically pure bicyclic ketones. Total synthesis of the diterpenoids (-)-Kolavenol and (-)-Agelasine B
… describes the synthesis of a series of enantiomerically pure cis-fused bicyclic trimethylstannyl ketones 124, 132 and 133. The bicyclic ketones were prepared by means of a methylenecyclohexane, methylenecyclopentane or anethylidenecyclopentane annulation sequence using the bifunctional …
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Ferriomethyl- und Wolframiomethyl-substituierte Silane, Silanole und Siloxane
Das Interesse an Übergangsmetall-substituierten Siloxanen ist in den vergangenen Jahren stark angewachsen. Dies ist vor allem darauf zurückzuführen, dass diesen Systemen eine wichtige Modellfunktion für auf Silica-Oberflächen verankerte, katalytisch aktive Übergangsmetallkomplexe zukommt, die eine …
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Early transition metal catalysts for the living polymerization of olefins and alkynes
… catalysts containing the [(2,6- C12C6H3NCH2CH2)2NMe]2- ([ArciN2NMe]2') ligand were prepared and employed in the polymerization of 1-hexene. Hafnium Ziegler-Natta catalysts containing the [(2,6- X2C6H3NHCH2)2C(CH3)(2-C5H4N)] ([Arx2NPy]2-) (X = Cl or F) ligand were also prepared for use in 1-hexene …
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Oxidation addition of H-H bonds to iridium: developing novel active water soluble catalysts for hydrogenation of unsaturates
The oxidative addition of H-H to iridium(l) trimethylphosphine complexes was studied and the reactivity of the resulting water soluble dihydrido iridium (III) complexes was investigated. One Dihydrido iridium(III) complex, mer-Ir(H)₂(PMe₃)₃CI <b>(2)</b> was characterized by ¹H, ³¹p and ¹³C NMR …
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Tripodal Inorganic 2-Pyridyl-phosphine Ligands and Unsymmetrical Analogues: Towards New Applications in Catalysis
… in the thesis. This chapter finishes with a statement of the aims of the thesis. Chapter 2 focuses on sterically-constrained C3-symmetric tris-2-pyridyl ligands and the effects of the substitution of the pyridyl rings at the 6-position on coordination to transition metal ions. The impact of such …
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Synthesis and application of rhodium(I) Fischer carbene complexes
… characterized via a carbene ligand transfer methodology from Group 6 Fischer carbene complex precursors and subsequent ligand modification. The classic Fischer route was followed towards the isolation of mono- and biscarbene complexes of the form [M(CO)5{C(OR)R'}] [M = Cr, W; R = Me, Et; R' = …
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Synthesis, characterization and liquid crystalline properties of organometallic complexes of chromium, cobalt and platinum
… in liquid crystal chemistry as they relate to metallomesogens, highlighting their advantages over purely organic liquid crystal systems. Chapter 2 reports on a mild synthetic route starting from [Co(DH)₂(py){(CH₂)ₘOH}] (DH = the monoanion of dimethylglyoxime; py = pyridine; m = 3 or 8) to give …
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Synthesis and reactivity of osmium-chromium oxidation catalysts and routes to a chiral analog
Osmium-chromium heterobimetallic complexes of the type (Y) (M(N)$\rm R\sb2(\mu$-O)$\rm\sb2CrO\sb2$) (Y = NBu$\sb4$, PPh$\sb4$; M = Os, Ru; R = Me, CH$\rm\sb2SiMe\sb3$, C$\rm\sb6H\sb5$) act as catalysts for the oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones …
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Synthesis of Functionalised Cobalt Sandwich Complexes for Application in Asymmetric Catalysis
… reaction of cobalt sandwich complex (η5-(N,N-dimethylaminomethyl)cyclopentadienyl)(η4-tetraphenylcyclobutadiene)cobalt with sodium tetrachloropalladate and N-acetyl-D-phenylalanine gave planar chiral palladacycle …
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Polar Tris(pyrazolyl)borates for the modeling of Zinc metalloenzymes in aqueous solution
… nature in the catalytic activity of zinc metalloenzymes. The zinc complexes of novel poly(pyrazolyl)borate ligands bearing polar substituents on the 3-position of the pyrazoles were expected to contribute to this. These comprise the carboxyester substituted BpC(O)OR,Me (R = Me, Et), the …
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Eta5-pentamethylcyclopentadienyl ruthenium complexes containing sulfur ligands
… of [Cp*RuCl2]2 towards organic substrates, (i) [Me2NC(S)S]2 and (ii) [Et2NC(S)S]2, isopropylxanthic disulfide (iii) [iPrOC(S)S]2 and bis(thiophosphoryl)disulfide (iv) [(iPrO)2P(S)S]2 produced air-stable Cp*Ru(S2CNR2)Cl2 (R = Me, 2.1; R = Et, 2.2), Cp*Ru(S2COiPr)Cl2 (2.3) and air-sensitive …
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